ext-boost/boost/iterator/iterator_concepts.hpp

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// (C) Copyright Jeremy Siek 2002.
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_ITERATOR_CONCEPTS_HPP
#define BOOST_ITERATOR_CONCEPTS_HPP
#include <boost/concept_check.hpp>
#include <boost/iterator/iterator_categories.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/and.hpp>
#include <boost/mpl/or.hpp>
#include <boost/static_assert.hpp>
// Use boost/limits to work around missing limits headers on some compilers
#include <boost/limits.hpp>
#include <boost/config.hpp>
#include <algorithm>
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#include <iterator>
#include <boost/concept/detail/concept_def.hpp>
namespace boost_concepts
{
// Used a different namespace here (instead of "boost") so that the
// concept descriptions do not take for granted the names in
// namespace boost.
//===========================================================================
// Iterator Access Concepts
BOOST_concept(ReadableIterator,(Iterator))
: boost::Assignable<Iterator>
, boost::CopyConstructible<Iterator>
{
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typedef BOOST_DEDUCED_TYPENAME std::iterator_traits<Iterator>::value_type value_type;
typedef BOOST_DEDUCED_TYPENAME std::iterator_traits<Iterator>::reference reference;
BOOST_CONCEPT_USAGE(ReadableIterator)
{
value_type v = *i;
boost::ignore_unused_variable_warning(v);
}
private:
Iterator i;
};
template <
typename Iterator
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, typename ValueType = BOOST_DEDUCED_TYPENAME std::iterator_traits<Iterator>::value_type
>
struct WritableIterator
: boost::CopyConstructible<Iterator>
{
BOOST_CONCEPT_USAGE(WritableIterator)
{
*i = v;
}
private:
ValueType v;
Iterator i;
};
template <
typename Iterator
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, typename ValueType = BOOST_DEDUCED_TYPENAME std::iterator_traits<Iterator>::value_type
>
struct WritableIteratorConcept : WritableIterator<Iterator,ValueType> {};
BOOST_concept(SwappableIterator,(Iterator))
{
BOOST_CONCEPT_USAGE(SwappableIterator)
{
std::iter_swap(i1, i2);
}
private:
Iterator i1;
Iterator i2;
};
BOOST_concept(LvalueIterator,(Iterator))
{
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typedef typename std::iterator_traits<Iterator>::value_type value_type;
BOOST_CONCEPT_USAGE(LvalueIterator)
{
value_type& r = const_cast<value_type&>(*i);
boost::ignore_unused_variable_warning(r);
}
private:
Iterator i;
};
//===========================================================================
// Iterator Traversal Concepts
BOOST_concept(IncrementableIterator,(Iterator))
: boost::Assignable<Iterator>
, boost::CopyConstructible<Iterator>
{
typedef typename boost::iterator_traversal<Iterator>::type traversal_category;
BOOST_CONCEPT_ASSERT((
boost::Convertible<
traversal_category
, boost::incrementable_traversal_tag
>));
BOOST_CONCEPT_USAGE(IncrementableIterator)
{
++i;
(void)i++;
}
private:
Iterator i;
};
BOOST_concept(SinglePassIterator,(Iterator))
: IncrementableIterator<Iterator>
, boost::EqualityComparable<Iterator>
{
BOOST_CONCEPT_ASSERT((
boost::Convertible<
BOOST_DEDUCED_TYPENAME SinglePassIterator::traversal_category
, boost::single_pass_traversal_tag
> ));
};
BOOST_concept(ForwardTraversal,(Iterator))
: SinglePassIterator<Iterator>
, boost::DefaultConstructible<Iterator>
{
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typedef typename std::iterator_traits<Iterator>::difference_type difference_type;
BOOST_MPL_ASSERT((boost::is_integral<difference_type>));
BOOST_MPL_ASSERT_RELATION(std::numeric_limits<difference_type>::is_signed, ==, true);
BOOST_CONCEPT_ASSERT((
boost::Convertible<
BOOST_DEDUCED_TYPENAME ForwardTraversal::traversal_category
, boost::forward_traversal_tag
> ));
};
BOOST_concept(BidirectionalTraversal,(Iterator))
: ForwardTraversal<Iterator>
{
BOOST_CONCEPT_ASSERT((
boost::Convertible<
BOOST_DEDUCED_TYPENAME BidirectionalTraversal::traversal_category
, boost::bidirectional_traversal_tag
> ));
BOOST_CONCEPT_USAGE(BidirectionalTraversal)
{
--i;
(void)i--;
}
private:
Iterator i;
};
BOOST_concept(RandomAccessTraversal,(Iterator))
: BidirectionalTraversal<Iterator>
{
BOOST_CONCEPT_ASSERT((
boost::Convertible<
BOOST_DEDUCED_TYPENAME RandomAccessTraversal::traversal_category
, boost::random_access_traversal_tag
> ));
BOOST_CONCEPT_USAGE(RandomAccessTraversal)
{
i += n;
i = i + n;
i = n + i;
i -= n;
i = i - n;
n = i - j;
}
private:
typename BidirectionalTraversal<Iterator>::difference_type n;
Iterator i, j;
};
//===========================================================================
// Iterator Interoperability
namespace detail
{
template <typename Iterator1, typename Iterator2>
void interop_single_pass_constraints(Iterator1 const& i1, Iterator2 const& i2)
{
bool b;
b = i1 == i2;
b = i1 != i2;
b = i2 == i1;
b = i2 != i1;
boost::ignore_unused_variable_warning(b);
}
template <typename Iterator1, typename Iterator2>
void interop_rand_access_constraints(
Iterator1 const& i1, Iterator2 const& i2,
boost::random_access_traversal_tag, boost::random_access_traversal_tag)
{
bool b;
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typename std::iterator_traits<Iterator2>::difference_type n;
b = i1 < i2;
b = i1 <= i2;
b = i1 > i2;
b = i1 >= i2;
n = i1 - i2;
b = i2 < i1;
b = i2 <= i1;
b = i2 > i1;
b = i2 >= i1;
n = i2 - i1;
boost::ignore_unused_variable_warning(b);
boost::ignore_unused_variable_warning(n);
}
template <typename Iterator1, typename Iterator2>
void interop_rand_access_constraints(
Iterator1 const&, Iterator2 const&,
boost::single_pass_traversal_tag, boost::single_pass_traversal_tag)
{ }
} // namespace detail
BOOST_concept(InteroperableIterator,(Iterator)(ConstIterator))
{
private:
typedef typename boost::iterators::pure_iterator_traversal<Iterator>::type traversal_category;
typedef typename boost::iterators::pure_iterator_traversal<ConstIterator>::type const_traversal_category;
public:
BOOST_CONCEPT_ASSERT((SinglePassIterator<Iterator>));
BOOST_CONCEPT_ASSERT((SinglePassIterator<ConstIterator>));
BOOST_CONCEPT_USAGE(InteroperableIterator)
{
detail::interop_single_pass_constraints(i, ci);
detail::interop_rand_access_constraints(i, ci, traversal_category(), const_traversal_category());
ci = i;
}
private:
Iterator i;
ConstIterator ci;
};
} // namespace boost_concepts
#include <boost/concept/detail/concept_undef.hpp>
#endif // BOOST_ITERATOR_CONCEPTS_HPP